This invention relates generally to gas turbine engines and more particularly, to cooling systems used to supply cooling air to gas turbine engine components.
Gas turbine engines typically include cooling systems to supply cooling air to components exposed to high temperatures. For example, at least some known gas turbine engines include cooling systems which supply air to pressurized sumps. More specifically, within such engines, a pair of ducts are used to route cooling air from a compressor stage to cooling plates positioned within the sumps.
During engine operation, the cooling air facilitates preventing an operating temperature of the cooling plates from increasing as a result of exposure to heat generated by the engine. The ducts may also be exposed to vibrational stresses induced by the engine during engine operation. Over time, continued exposure to the vibrational and thermal stresses may damage one of the cooling supply ducts. More specifically, such stresses may cause duct breaks. Depending on a severity of the damage to the duct, the cooling air may flow through the duct break rather than into the sump. Furthermore, because the sump is pressurized, cooling air supplied to the sump by the other duct may be exhausted from the sump through the broken duct, thus increasing an operating temperature of the cooling plates. Over time, continued exposure to the higher operating temperatures may damage the cooling plates.
In one aspect, a check valve is provided. The check valve includes a valve housing and at least one control member. The valve housing includes a sidewall and an opening extending therethrough. The sidewall defines the opening and includes at least one recess formed therein. Each control member is rotatably coupled to the valve housing within the sidewall recess, and each control member is configured to allow flow of fluid through the valve opening in a first direction. Each control member is further configured to substantially prevent flow of fluid through the valve opening in a second direction that is opposite the first direction.
In another aspect, a method for operating a gas turbine engine is provided. The method includes directing fluid downstream from a cooling air supply duct through a check valve that includes a hollow valve housing including a sidewall that has a recess formed therein and at least one control member that is rotatably coupled to the check valve within the recess. The method also includes preventing fluid from flowing upstream into the supply duct with the check valve.
In a further aspect, a gas turbine engine cooling air supply system is provided. The cooling air supply system includes a cooling air supply duct including an end, and a check valve. The check valve is coupled to the cooling air supply duct end and is configured to permit fluid flow from the cooling air supply duct while substantially preventing fluid flow into the cooling air supply duct, and includes a hollow valve housing and at least one control member. The valve housing includes a sidewall and an opening that extends therethrough. The sidewall defines the opening and includes at least one recess formed therein. The control member is rotatably coupled to the valve housing within the sidewall recess.